A 6-week-old baby born with microcephaly is treated in Recife, Brazil, on Jan. 29. (Mario Tama/Getty Images)

IF RUNAWAY disease were not a disturbing enough nightmare for most people, there is a knock-on effect often just as disruptive: panic, confusion and fear. When a silent killer is on the march and authorities react by dissembling or with desperation, people get the message — and get irrational. The case of Ebola virus disease in West Africa demonstrated vividly how, in managing an outbreak, good information is as important as medical therapy, and failure to inform can lead to disaster. Now the Zika virus, while not as deadly as Ebola, is highlighting again the need for honesty, transparency, and a renewed commitment to research and rapid response in managing such threats.

The Zika virus existed for decades in equatorial zones of Asia and Africa. Then, about 10 years ago, it cropped up on various Pacific islands. The virus, borne by mosquitoes, causes a mild, flu-like sickness and rash in some infected people, and there is no known therapy. Zika showed up in Brazil last year and now has infected more than 1 million people, and, most worrisome, has been linked to a condition known as microcephaly, in which a child is born with a small head and brain. The Brazilian authorities made the connection because a surge of microcephaly — more than 4,000 cases — emerged about the time the Zika virus arrived, and there is evidence the virus was present in a small number of children and their mothers. Much more needs to be known about the link, however.

In El Salvador, the government did not wait for further tests, and suddenly advised all women in the country to delay getting pregnant until 2018. Aside from the Big Brother attitude, the advice seemed to signal desperation. The announcement did, perhaps, serve as a crude wake-up call for women who are pregnant or might become pregnant to pay attention, and the U.S. Centers for Disease Control and Prevention has urged all pregnant women to avoid travel to areas where the virus has been found.

The virus is certain to spread in the months ahead — by some estimates, to 3 million or 4 million people. The World Health Organization has warned it is “spreading explosively.” The most responsible action by authorities is to fight mosquitoes and the conditions in which they breed, and help people grasp the basics, such as protecting themselves against mosquito bites that can infect.

The spread of a new or unusual disease — whether it be severe acute respiratory syndrome a decade ago, or Middle East respiratory syndrome a few years ago, or Zika now — also raises an important challenge to biomedical researchers. There’s been a hope that gains in genomics and other disciplines could lead to a rapid-response mechanism for fighting such threats. Had a vaccine been successfully developed quickly for Ebola, thousands of lives might have been saved. It is not easy to bend the rules of nature and create effective vaccines and drugs quickly. But the arrival of Zika should remind us that basic and applied research to this end is well worth the investment.